<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Capture.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Cache_Core
 */
require_once 'Zend/Cache/Core.php';

/**
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Cache_Frontend_Capture extends Zend_Cache_Core {
	/**
	 * Page identifiers
	 * @var array
	 */
	protected $_idStack = array ();
	
	/**
	 * Tags
	 * @var array
	 */
	protected $_tags = array ();
	
	protected $_extension = null;
	
	/**
	 * Start the cache
	 *
	 * @param  string  $id Cache id
	 * @return mixed True if the cache is hit (false else) with $echoData=true (default) ; string else (datas)
	 */
	public function start($id, array $tags, $extension = null) {
		$this->_tags = $tags;
		$this->_extension = $extension;
		ob_start ( array ($this, '_flush' ) );
		ob_implicit_flush ( false );
		$this->_idStack [] = $id;
		return false;
	}
	
	/**
	 * callback for output buffering
	 * (shouldn't really be called manually)
	 *
	 * @param  string $data Buffered output
	 * @return string Data to send to browser
	 */
	public function _flush($data) {
		$id = array_pop ( $this->_idStack );
		if ($id === null) {
			Zend_Cache::throwException ( 'use of _flush() without a start()' );
		}
		if ($this->_extension) {
			$this->save ( serialize ( array ($data, $this->_extension ) ), $id, $this->_tags );
		} else {
			$this->save ( $data, $id, $this->_tags );
		}
		return $data;
	}
}
